Top 5 SNL impressions

Kate McKinnon's Justin Bieber and Ellen DeGeneres are part of a 40-year tradition of SNL performers doing great impressions. Things have changed, of course, and Eddie Murphy's Buckwheat and Billy Crystal's Sammy Davis Jr. - in blackface yet - haven't aged that well. Here's a list of the best - and I'm not including impressions that, say, Martin Short brought from SCTV.